this one has an unlisted workshop. The open doors are not completely clear, but most evident on the right side of the door.
Constantine II
A.D. 326
CONSTANTINVS IVN NOB C; laureate, draped and cuirassed bust right.
VIRTV-S AVGG camp gate, four turrets, doors open, star above, P/R in fields.
In ex. R Q
RIC VII Rome 193